import yaml


data = {
    "num":[
        [99, -99, 0],
        [98, -98, 0],
        [-99, -98, -197],
        [-1.2, 1, -0.2]
    ]
}

with open("data/data.yaml", "w", encoding="utf-8") as f:
    yaml.dump(data, f,allow_unicode=True)